#include <iostream>
using namespace std;
int main ()
{
    cout<<"Vvedite chisla"<<endl;
    double A,B;
    cin>>A;
    cin>>B;
    if (B==0)
    {
        cout<<"Osibka!!!"<<endl;
        return 0;
    }
    cout<<"Kakaya operaziya?"<<endl;
    int N;
    cin>>N;
    switch (N)
    {
    case 1: cout<<A+B;
        break;
    case 2: cout<<A-B;
        break;
    case 3: cout<<A*B;
        break;
    case 4: cout<<A/B;
        break;
    default: cout<<"Nepravilno vvel operaziu";
    }
        return 0;

}
